# On maps, why is North always up. **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [August 24, 2010, 2:34pm UTC](https://boards.straightdope.com/t/on-maps-why-is-north-always-up/551293 "2010-08-24T14:34:45Z")\ **Posts on this page:** 6\ **Page:** 2
**Author:** ![gnoitall](https://avatars.discourse-cdn.com/v4/letter/g/bb73d2/32.png) [@gnoitall](https://boards.straightdope.com/u/gnoitall)\ **Post date:** [August 26, 2010, 5:15pm UTC](https://boards.straightdope.com/t/on-maps-why-is-north-always-up/551293/21 "2010-08-26T17:15:53Z")
> [@Lemur866](#): > > [QUOTE=John W. Kennedy;12840919 > Putting the equator nearer the bottom is not necessary, but, because the Mercator projection _can’t_ go all the way to the poles (they’re infinitely far away), which means that you have to pick a northern and a southern latitude to cut it off, and because Spitzbergen is further north than the Cape of Good Hope is south and most people aren’t really interested in the details of Antarctica, you can cut off more of the Southern Hemisphere with no important loss.[/QUOTE] > > No, the Mercator projection CAN go all the way to the poles, it’s just that the poles are represented by a line rather than a point. Actually, come to think of it, Lemur866 is right. You really can’t cross the poles on a normal Mercator projection. I was confused earlier. That means that you can continue on a constant heading forever. Your apparent projected ground track will simply become shorter and shorter as you approach the pole. ---
**Author:** ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)\ **Post date:** [August 26, 2010, 5:23pm UTC](https://boards.straightdope.com/t/on-maps-why-is-north-always-up/551293/22 "2010-08-26T17:23:14Z")
As I said, you can’t get to the poles on a Mercator, because they’re infinitely far away. (The lines of longitude are represented as parallel lines, and parallel lines never meet.) But you _do_ keep the same compass heading as long as you follow a straight line (assuming true, rather than magnetic headings). It’s the defining characteristic of the projection, and its _raison d’être_. ---
**Author:** ![JoelUpchurch](https://avatars.discourse-cdn.com/v4/letter/j/f05b48/32.png) [@JoelUpchurch](https://boards.straightdope.com/u/JoelUpchurch)\ **Post date:** [August 26, 2010, 5:26pm UTC](https://boards.straightdope.com/t/on-maps-why-is-north-always-up/551293/23 "2010-08-26T17:26:29Z")
> [@Floater](#): > > > [@Ignatz](#): > > > > He preferred to draw his site plat maps with the viewer looking (up) into the entrance to the development site. > > In orienteering you always hold your map so that whatever direction is in front of you is up. All the GPS system I’ve tried use this convention. I had one that a North is up option that I tried, but I quickly went back to front is up. If you use Google Earth, then up is whatever direction you want. ---
**Author:** ![Gedd](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gedd/32/4938_2.png) [@Gedd](https://boards.straightdope.com/u/Gedd)\ **Post date:** [August 26, 2010, 6:15pm UTC](https://boards.straightdope.com/t/on-maps-why-is-north-always-up/551293/24 "2010-08-26T18:15:00Z")
> [@Civil\_Guy](#): > > **GHO57** : > > …So your country’s going to deny having anything to do with supplying Santa Claus (also known as Saint Nicholas, Sinterklaas, Father Christmas - fellow’s got a lot of aliases, suspicious all by itself) with magical reindeer, huh? “He sees you when you’re sleeping, he knows when you’re awake. He know’s if you’ve been bad or good . . .” To quote a _Calvin and Hobbes_ cartoon, “Santa Claus: Kindly old elf, or CIA spook?” :dubious: ---
**Author:** ![Powers](https://avatars.discourse-cdn.com/v4/letter/p/edb3f5/32.png) [@Powers](https://boards.straightdope.com/u/Powers)\ **Post date:** [August 26, 2010, 6:26pm UTC](https://boards.straightdope.com/t/on-maps-why-is-north-always-up/551293/25 "2010-08-26T18:26:41Z")
> [@John\_W.Kennedy](#): > > As I said, you can’t get to the poles on a Mercator, because they’re infinitely far away. (The lines of longitude are represented as parallel lines, and parallel lines never meet.) While what you say is true about the Mercator, there are other parallel-meridian projections that do not have the poles at infinite distance. > **[Equirectangular projection](https://en.wikipedia.org/wiki/Plate_carr%C3%A9e_projection)** > > The equirectangular projection (also called the equidistant cylindrical projection or la carte parallélogrammatique projection), and which includes the special case of the plate carrée projection (also called the geographic projection, lat/lon projection, or plane chart), is a simple map projection attributed to Marinus of Tyre who, Ptolemy claims, invented the projection about AD 100. > The projection maps meridians to vertical straight lines of constant spacing (for meridional intervals of cons... Powers &8^] ---
**Author:** ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)\ **Post date:** [August 27, 2010, 8:44pm UTC](https://boards.straightdope.com/t/on-maps-why-is-north-always-up/551293/26 "2010-08-27T20:44:37Z")
> [@JoelUpchurch](#): > > > [@Floater](#): > > > > In orienteering you always hold your map so that whatever direction is in front of you is up. > > All the GPS system I’ve tried use this convention. I had one that a North is up option that I tried, but I quickly went back to front is up. > > If you use Google Earth, then up is whatever direction you want. Back in the old days (the 90s), when having a GPS meant having a GPS sensor attached to your laptop (actually, you can still get such a configuration, if you want it), you might have a north-up overview combined with a forward-up detail. Modern hand-size devices can’t afford the screen real-estate. [Previous page](https://boards.straightdope.com/t/on-maps-why-is-north-always-up/551293.md?page=1)